The present invention relates to lubrication in bearing assemblies, and in particular, to high speed bearing assemblies with under race lubrication used in gas turbine engines.
Bearing assemblies are integral to the performance and speed of gas turbine engines. To reduce wear on bearing assemblies, it is essential that lubricating fluid, such as oil, be delivered to the bearing assemblies to keep them cool and clean. Under race oil delivery (channeling oil under the bearing) is a method for delivering oil to bearing assemblies in gas turbine engines that uses less oil to achieve bearing temperatures that are cooler and more uniform than those reached by other less-oil-efficient methods, such as using side scoops, wings and side jets to direct oil into the bearing assemblies.
A known implementation of under race oil delivery to prior art bearing assemblies in aerospace applications is to utilize axial grooves or slots formed on an inside surface of an inner ring of the prior art bearing assembly that extend the entire inside length of the prior art inner ring. Radial ports or holes extend through a thickness of the prior art inner ring and intersect the axial slots. After the prior art inner ring and its corresponding bearing assembly have been mounted to a shaft, lubricating oil is directed into the axial slots where at least a portion of the oil enters the radial holes and exits inside the prior art bearing assembly where lubrication is needed. The remainder of the oil continues through the axial slots where it is directed to other parts that mate with the prior art bearing assembly.